Skip to content
RunupLab

Free sim

3D Windsock

The windsock is the one instrument every airport gives you for free — if you know how to read it. It points downwind, away from where the wind is coming from, and its shape is the speed gauge. Set the wind, fire a gust, and watch the fabric inflate, sag, swivel, and flutter in response.

Inputs
KT
°
Drag to orbit · Scroll to zoom · Double-click to reset

Wind 12 knots from 270 degrees, the west. The sock reads flying. Gusts to 24 knots, where it reads fully extended.

The sock points downwind — away from where the wind is from — and its shape is the speed gauge: hanging limp near calm, filling through the single digits, and fully extended and rigid from about 15 knots — the wind an FAA-specification sock is built to extend fully in (AC 150/5345-27F § 3.2.2; source below).

Source. FAA Advisory Circular 150/5345-27F, FAA Specification for Wind Cone Assemblies (AC 150/5345-27F, 15 December 2021), § 3.2.2, p. 3-1 — the sock is designed to fully extend at 15 knots; § 3.5, p. 3-3 — it must swing freely from 3 knots and show direction within ±5°. Retrieved from faa.gov 2026-09-08 and frozen in this site’s repository, where a test checks every quoted phrase against that copy. That is a design requirement for FAA-specification socks; a sock that does not meet it may read differently. The sock's shape at each speed in this sim is a visual model tuned to look right, not a calibration.

Now put it over an airport

The same sock stands midfield in the Traffic Pattern sim — where it tells you which runway to want — and next to the maneuver field in Ground Reference Maneuvers.

Free, no signup needed

Next step

The Private Pilot Quick-Review Study Guide covers this in chapter 5 (airport operations). It is in CFI review and not on sale yet; the guide page has the list for launch notes.